Conventionally, as an ink supply device for an inkjet recording apparatus having a plurality of recording heads, an inkjet recording apparatus having the following configuration (see FIG. 3) has been known.
More specifically, in the inkjet recording apparatus, ink is self-supplied by being discharged to individual heads 151 from an intermediate tank 131 via a supply valve 133, a common flow path 134, a distributor 141, and an individual head supply path 145 during recording.
The ink is sent by a liquid-sending pump 122 from an ink tank 111 via a replenishment flow path 121 when a bulge detection sensor 132 determines that replenishment is required, and is replenished by a predetermined amount to a replenishment valve 123 and the intermediate tank 131.
The distributor 141 provided halfway in the common flow path 134 is provided to make a flow path resistance of ink to be supplied to the individual heads 151 constituting a recording head 150 uniform and functions as a supply source for a short time.
When the recording head 150 is recovered, an atmosphere communication shutoff valve 143 disposed in an upper part of the distributor 141 is opened, to reverse the liquid-sending pump 122 and slightly suck air in the distributor 141 serving as a part of an ink flow path, and is closed.
Then, the ink is sent by rotating the liquid-sending pump 122 forward, and is extruded by a nozzle of the individual head 151 selected by the individual head valve 146 via a replenishment valve 125 and a pressure flow path 124 for bypassing the intermediate tank 131.
After dripping of the ink from the nozzle of the individual head 151 is stopped, a nozzle surface is wiped by a wiper blade 161 disposed on a maintenance stand 160.
An air vent flow path 171 having an air vent valve 144 is installed from the upper part of the distributor 141, and air is discharged from the flow path during initial introduction of the ink and when air is mixed into an ink supply path (see Patent Document 1).
Conventionally, the following has been known as an inkjet recording apparatus for controlling the viscosity of ink flowing through a recording head.
More specifically, an inkjet recording apparatus in which each of the recording head, a tank, and a supply pipe is provided with a cartridge heater or a heater while being provided with a first temperature sensor, a second temperature sensor, and a third temperature sensor, and a temperature control unit controls each of the temperatures of the recording head, the tank, and the supply pipe to a most suitable temperature has been known (see Patent Document 2).